1. Field of the Invention
The present invention relates to a novel ingredient and the use of same. More particularly, it relates to molecules/compounds that are 2-substituted-3,3-diphenyl-2-propenoic acids reacted with [A] a C16 to C50 straight or branched chain, substituted or unsubstituted, conjugated or non-conjugated hydrocarbon, or [B] a siloxane, polysiloxane or organo-modified polysiloxane residue. When there is a C16 to C50 chain and it is also a substituted hydrocarbon, the substitutions to the hydrocarbon chain can be an amine, an amide, a hydroxyl, an alkoxy, an alkyl, a halogen, a nitrogen, a sulfonyl, nitrile, or phenyl. Even more particularly, the present invention relates to the use of the new molecules in sunscreen compositions to provide protection against the harmful effects caused by ultraviolet radiation. The present invention also relates to methods for providing ultraviolet radiation protection while also providing increased UV absorbance, photostabilization, substantivity, waterproofing, water resistance, sweat proofing, sweat resistance, and/or rub off resistance in cosmetic and personal care compositions.
2. Description of the Related Art
Commercial sunscreen compositions commonly employ a sunscreen active, such as a dibenzoylmethane derivative, e.g. butylmethoxydibenzoylmethane (avobenzone). A common problem associated with some sunscreen compositions is a tendency of sunscreen actives, including dibenzoylmethane and/or derivatives thereof, to photodegrade over time from exposure to UV (ultraviolet) light, e.g. lack of photostabilization. This results in an alteration of the UV absorbance of the composition and, thus, a diminution in sunscreen protection for the user during extended exposure to sunlight.
U.S. Pat. No. 5,952,391 relates to sunscreen compositions having dibenzoylmethane sunscreen actives. The compositions have flavone or flavanone derivatives to stabilize the dibenzoylmethane actives.
Current esters of 2-cyano-3,3-diphenyl-2-propenonic acid have short chain alcohols for ease of use. U.S. Pat. No. 6,416,773 modified the commercially available esters by reacting the acid with a cyclic alcohol. This change has resulted in crystalline solids with poor solubility that require the addition of solvents that were not preferred for optimal efficacy, aesthetics, and stability. Consequently, these esters are not ideally suited for cosmetic formulations.
Besides photostabilization, suncare formulations also strive for water, perspiration and wear resistance. Additionally, a desired property of sunscreens is protection from both UVB and UVA wavelengths, as well as increased coverage of the skin.
It is desired to have a sunscreen composition that is photostable and affords the claimed sunscreen protection for an extended period of time. It is also desired to have a sunscreen composition that provides: water, perspiration and wear resistance; photostabilization of dibenzoylmethane and its derivatives and other sunscreens; a synergistic increase in UV absorbance with dibenzoylmethane derivatives; and a cumulative boost of UV absorbance in the erythemal action spectra of UV light. It is further desired to have such a photostable sunscreen composition that affords an enhanced degree of sunscreen protection from a broad spectrum of both UVB and UVA wavelengths, and that also offers improved coverage of the skin.